diff --git a/.gitignore b/.gitignore
index f6aa017..3491655 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,5 @@ resources/icons/*-light
 /coverage
 *.js
 package-lock.json
+*.pdf
+*.gv
diff --git a/pikchr/pikchr.tmLanguage.json b/pikchr/pikchr.tmLanguage.json
index f39a7bb..bf2185f 100644
--- a/pikchr/pikchr.tmLanguage.json
+++ b/pikchr/pikchr.tmLanguage.json
@@ -126,7 +126,7 @@
       ]
     },
     "basetype-classname": {
-      "begin": "(?<=^|;|:)\\s*(?:\\b(arc|arrow|box|circle|cylinder|diamond|dot|ellipse|file|line|move|oval|spline|text)\\b|(\".*\"))\\s*",
+      "begin": "(?<=^|;|:|{)\\s*(?:\\b(arc|arrow|box|circle|cylinder|diamond|dot|ellipse|file|line|move|oval|spline|text)\\b|(\".*\"))\\s*",
       "beginCaptures": {
         "1": {
           "name": "storage.type.class.pikchr"
@@ -393,13 +393,17 @@
     },
     "boolproperty": {
       "comment": "Properties with no argument",
-      "match": "(<->|<-|->)|\\b(cw|ccw|invis(ible)?|thick|thin|solid|same|chop|fit)\\b\\s*",
+      "match": "(<->|<-|->)|\\b(cw|ccw|invis(ible)?|thick|thin|solid|same|chop|fit)\\b|(&(?:larr|leftarrow|leftrightarrow|rarr|rightarrow);)\\s*",
       "captures": {
         "1": {
           "name": "entity.name.tag.pikchr"
         },
         "2": {
           "name": "entity.name.tag.pikchr"
+        },
+        "4": {
+          "comment": "obscure pikchr constants",
+          "name": "entity.name.tag.pikchr"
         }
       }
     },
diff --git a/pikchr/test/advanced.test.pikchr b/pikchr/test/advanced.test.pikchr
index ea0b5e3..4accbfa 100644
--- a/pikchr/test/advanced.test.pikchr
+++ b/pikchr/test/advanced.test.pikchr
@@ -86,3 +86,11 @@ box "expr" fit with .w at 1.75*$h below BTW.w
 //                                      ^^^ variable.language.pikchr
 //                                         ^ punctuation.separator.period.pikchr
 //                                          ^ entity.name.class.pikchr
+
+define square { box ht $7 wid $8 $9 }
+// <------ keyword.control.directive.define.pikchr
+//     ^^^^^^ variable.language.pikchr
+//            ^ punctuation.section.block.begin.bracket.curly.pikchr
+//              ^^^ storage.type.class.pikchr
+//                  ^^    ^^^ support.constant.property-value.pikchr
+//                     ^^     ^^ ^^ variable.language.pikchr
diff --git a/pikchr/test/boolproperty.test.pikchr b/pikchr/test/boolproperty.test.pikchr
index 828d5d6..fc57fe9 100644
--- a/pikchr/test/boolproperty.test.pikchr
+++ b/pikchr/test/boolproperty.test.pikchr
@@ -38,3 +38,18 @@ cylinder same
 box same;
 // <--- storage.type.class.pikchr
 //  ^^^^ source.pikchr entity.name.tag.pikchr
+
+arrow &rarr;
+//    ^^^^^^ entity.name.tag.pikchr
+
+arrow &rightarrow;
+//    ^^^^^^^^^^^^ entity.name.tag.pikchr
+
+arrow &larr;
+//    ^^^^^^ entity.name.tag.pikchr
+
+arrow &leftarrow;
+//    ^^^^^^^^^^^ entity.name.tag.pikchr
+
+arrow &leftrightarrow;
+//    ^^^^^^^^^^^^^^^^ entity.name.tag.pikchr